Fire and heat proved to be a brutal combination for Chicago firefighters in Little Village Thursday night. The heat was so severe one firefighter had to be treated for heat-related problems. Nearby, other crews hopped into a supply truck filled water jugs, and hoisted them onto their shoulders, headed for the troops. No one suffered serious injuries.

The heat also resulted in tragedy. Lake County authorities say a 62-year-old boater jumped into a lake near Antioch to cool off. His 69-year-old friend tried to rescue him. Crews saved him, but the younger man is still missing.

"It is difficult for search and rescue crews simply because of the heat," said Sgt. Karen Kates, Lake County Sheriff's Office.

At Union Station, Metra trains were delayed because officials say the heat stresses the tracks and signals.

"Who knows when I'm going to get home," said Maria Manhart, another delayed commuter.

If it continues, the extreme heat may cause more problems.

"We usually see more coming in for heat-related illness as the heat wave rolls on. Not necessarily the first or second day," said Dr. John Williams, Emergency Medicine, University of Illinois Hospital.

The heat may just depend on your perspective.

"It's cool almost to me, I know that sounds funny right? I could put a sweater on right now. I really could," said Michelle Padilla, a tourist from Arizona.